Field of the Invention
The present disclosure relates to systems and methods for determining header data relating to a message; and in particular to determining header data which is other than that provided in a message.
Description of the Related Technology
Messages, such as HTTP requests and other similar network messages contain header data which identifies, amongst other things, the type of application sending the message, and the format for any desired response. For example, the “user-agent” header field in a HTTP request identifies the type of browser (i.e. application) which sent the HTTP request.
In some cases some fields within the header data are omitted or contain erroneous or ambiguous data. For instance, a browsing application (e.g. Safari or Chrome) may be available in different versions, one for a desktop computer and another for mobile telephone, but may fail to specify which version is sending the message. A further example, often described as spoofing, is where the user-agent header field identifies an application other than the one sending the message. This may be done to achieve a certain effect, such as enabling a browser on a mobile device such as a smart phone to retrieve a webpage formatted for a desktop browser, and vice versa.
Incorrect, incomplete or omitted header data, whether done deliberately or not, can cause problems. Therefore, it is desirable to be able to have a method of determining header data for a message.